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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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MAIASPINA GLACIER                                         45
sented in former times in many parts of the Rocky, Cascade and Coast Ranges of western United States and Canada when glaciers flowed down, these mountain valleys to the base. The type may very well have appeared in Norway and Great Britain as the ice sheets of the Glacial Period advanced from the highlands, and again as the waning ice sheets shrank back toward the highland areas. In the Alps, too, conditions favoring the development of piedmont glaciers appeared. Indeed, wherever mountain glaciers passed beyond their mountain valleys out upon level land, expanded piedmont bulbs must have formed, as in the valleys of the Italian lakes south of the Alps; and where two or more such bulbs coalesced piedmont glaciers resulted, as upon the plateau north of the Alps. For the interpretation of the evidence of such former piedmont glaciers the study of the conditions on and around the Malaspina Glacier throw much light. The resemblance of those piedmont glaciers which have vanished to those which still exist in Alaska in the main features, both of form and deposits, must have been great, for in both cases the conditions of supply are similar, and in both cases the conditions of wastage in a cool temperate climate are alike.
Early Observations on the Malaspina. The early explorers of the eighteenth century seem to have recognized the glacial character of this great ice mass, for Vancouver, in describing Icy Bay in 1794,1 says he saw a "high abrupt cliffy point forming the west point of a bay, bounded by a solid body of ice or frozen snow." Tebenkof's Icy Bay chart of 1848 (Fig. l), based upon the log books of several Russian explorers sent out in 1788 and from 1793 to 1807, shows eight miles of glacier fronting on Icy Bay behind which is a surface supporting trees.3 Belcher in 1837 8 says that "the whole of this bay and the valley above it was now found to be composed of (apparently) snow ice about thirty feet in height at the water cliff. . . . The small bergs or reft masses of ice, forming the cliffy outlines of the bay, were veined and variegated by mud streaks like marble, and where they have been exposed to the sea were excavated into arches, etc., similar to our chalk formations. ... In Icy Bay the apparently descending ice from the mountains to the base was in irregular broken masses." Vancouver also said, "As the vessel advanced along the coast from Point Riou the country became less woody, and beyond the low, projecting point it seemed only to produce a brownish vegetation, which further to the eastward entirely disappeared, and presented a naked, barren country, composed apparently of loose unconnected stones of different magnitudes." Tebenkof described the low country between Mt, St. Elias and the sea as a forest-covered tundra where "through cracks in the gravelly soil, ice could be seen beneath."
Possible Great Advance of the Malaspina. These statements, some of which have been quoted previously by Russell * and by Davidson,5 assign to the Malaspina Glacier such different conditions from those observed since 1890 that one is led to question whether the difference can be entirely due to failure of observation. A possible explanation of the difference may be that before 1794 Malaspina Glacier had undergone a long period of stagnation and recession resulting in the ablation-moraine surface of "naked barren
i Vancouver, Capt. George, Voyage of Discovery, Vol. V, 1801, pp, 849, 851.
* Tebenkof, Capt. Michael, Hydrographic Atlas and Observations, with. 48 charts.   St. Petersburg, 1848 and 1852.
' Belcher, Capt. Sir Edward, Narrative of a Voyage Round the "World, London, 1848, Vol. I, pp. 79-80. «Russell, I. C., Nat. Geog. Mag., Vol. HI, 1891, pp. 66-^70.
• Davidson, George, The Glaciers of Alaska that are Shown on Russian Charts or Mentioned in Older Narratives, Trans, and Proc. Geog. Soc. Pacific, Vol. HI, 1904, pp. 48-47, and Map VI.